Rocket stabilizing fins



Nov. 18, 1947. E. G. UHL ETAL ROCKET STABILIZING FINS Filed Jan. .8, 1944 Edward E Uh] Lee-lie A- 516111121 222, c. JPWOmMM Patented Nov. 18, 1947 ROCKET STABILIZIN G FIN S Edward G. Uhl, Elizabeth, N. J., and Leslie A. Skinner, Washington, D. 0., assignors to the United States of America, as represented by the Secretary of War Application January 8, 1944, Serial No. 517,530 1 Claim. (Cl. 102-50) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) 1 The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

2 holes I I in fins l and lies in groove 5. The ends of wire l2 are then suitably secured together by twisting or soldering. The wire I2 may be further secured within groove by upsetting the sides of This invention relates to flight stabilizing fins 5 flange 4 into groove 5 as indicated at l3 in Fig. 2 for a rocket projectile, more particularly to colmidway between each of the fins l. A rounded lapsible stabilizing fins therefor, corner i is provided on the squared end of each It is an object of this invention to provide imfin T to permit the fins l to pivot about wire l2. proved collapsibly mounted stabilizing fins for a As previously mentioned fins l are mounted rocket projectile. with tabs 8 facing the head of the projectile (not The specific nature of the invention as Well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Fig. 1 is a fragmentary side view of a rocket projectile partly in longitudinal section with the fins in the collapsed position showing the manner of mounting such fins about the periphery of the rocket nozzle.

Fig. 2 is a fragmentary side elevational view of the rocket showing the collapsible fins in the extended position.

Fig. 3 is a right end elevational view of Fig. 1 showing the ends of the collapsed fins.

Fig. 4 is a side elevational view of the nozzle showing in detail the grooved and slotted flange utilized for pivotally mounting the collapsible fins.

Fig. 5 is a right end elevational view of Fig. 4.

Referring to the drawing wherein like characters refer to similar parts there is shown in Fig. 1 a rocket projectile embodying this invention. A nozzle 2 having an interior of conventional Venturi construction commonly employed in rocket projectiles is secured to a rocket motor housing I as by threads 3. An integral flange 4 is provided about the outer periphery of nozzle 2. An annular groove 5 is provided about the periphery of flange 4 and is centrally located therein. A plurality of equally disposed transverse slots 6 are provided about flange d for mounting fins 1, one fin in each of such slots.

Fin 1 comprises a thin strip of metal having a short tab 8 on one end bent at right angles to th body portion of each fin 1. Each tab 8 is also sloped as shown in Fig. 2 so that the air resistance forces on the fins during flight of the projectile will maintain the fins in extended posishown). Thus when the projectile is launched the tabs 8 being at a substantial angle to the axis of the projectile will be forced outwardly to the extended position shown in Fig. 2. The fins I are stopped in this extended position by the end I5 of each fin engaging the bottom of slots 6 and they will be maintained in such position as long as the projectile is in flight by the air pressure against the fins.

In the practice of this invention it was discovered that an even number of fins, preferably six fins as shown in the accompanying drawing, proved highly satisfactory. Greatly improved stabilizing eflects were obtained in flight trials with rockets embodying this invention when the tabs 8 were bent alternately in a right hand and a left hand direction and each pair of opposed fins spaced 120 apart as shown in Fig. 3.

It is thus apparent that a simple and easily manufactured positive securing means for pivotally mounting collapsible fins on a rocket projectile is hereby provided.

We claim:

In a rocket projectile the improvement comprising a projecting flange around the periphery of the rocket projectile, an annular groove in said flange, a plurality of fins, each of said fins having a hole in one end thereof, means on said flange for receiving said fins in spaced relation about the periphery of the flange and with said holes aligned with said annular groove, each of said fins having a portion at its distal end bent transversely to the plane of the fin, and said fins being disposed on said projectile in equi-spaced groups of two adjacent fins, each group having their bent end portions in mutually facing relation and. a fastener traversing said holes and said annular groove whereby said fins are pivotally secured to said flange.

tion. A small rectangular notch 9 is provided in EDWARD UI-IL,

the other end l5 of fin 1 thereby forming a stop LESLIE A. SKINNER. surface I0. Each fin I is then inserted in a corresponding slot 6 in flange 4, with tab 8 facing REFERENCES CITED forwardly or to the right as sh wn in g. S0 The following references are of record in the that notch 9 rests on top of nozzle 2 and stop file of t i patent:

surface [0 abuts the forward end of nozzle 2. A transverse hole H is provided in each fin 1 and UNITED STATES PATENTS is so positioned that when fins I are mounted on Number Name Date nozzle 2 the holes II will be aligned with groove 1,166,879 Alard Jan. 4, 1916 5. A wire i2 is then threaded thru each of the 1,879,840 Brandt Sept. 27, 1932 

